Combined reinforcing-plate and key-lug for brake-shoes.



w. H. McDONDUGH. COMBINED REINFORCING PLATE AND KEY LUG FOR BRAKE SHOES.

APPLICATION FILED SEPT-2% I916- 1,226,545. PatentedMaylti, 1917.

UN STATES PATENT OFFICE.

WILLIAM H. MGDONOUGII, OF NEW YORK, N. Y., ASSIGNOR, BY MESN E ASSIGNMENTS,

TO THE AMERICAN BRAKE SHOE ANID FOUNDRY COMPANY, OF WILMINGTON, DELA- WARE, A CORPORATION OF DELAWARE.

COMBINED REINFORCING-PLATE AND KEY-LUG FOR BRAKE-SHOES.

Specification of Letters Patent.

Patented May 15, 1917.

Original application filed April 25, 1916, Serial No. 93,362. Divided and this application filed September 29, 1916. Serial No. 122,801.

The invention relates to brake shoes and particularlyto the reinforcing back plate and key lug employed in connection with such devices, the present application being divided from my .copending application Serial Number 93,362, filed April 25, 1916.

The object of the invention is to provide an integral key lug and back plate for brake shoes, and means to reinforce the structure at the point where the key lug is formed.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown by the accompanying drawing, and finally pointed out in the appended claims.

Figure 1 is a plan view of a combined brake shoe back and key lug embodying my invention.

Fig. 2 is a sectional view of the same taken on the line 22- Fig. 1.

Fig. 3 is a similar view of a modified arrangement embodying my invention.

The same part is designated by the same reference numeral. wherever it occurs throughout the several views.

It is a common practice in the manufacture of brake shoes to apply a reinforcing back plate of ductile metal, such as sheet steel, to the cast metal shoe body, and to form a key lug for attaching the shoe to the brake head by transversely bending the back plate centrally into an integral loop with openings through the transversely extending walls of the loop for the passage of the securing key. Such structure however, interrupts the continuity of the back plate, leaving the space across the throat of the integral key lug unprotected and without reinforcement. As the greatest strains, in use, are imposed on the device at the key lug, it will be seen that in the construction referred to, and without reinforcement of the back plate across the throat of the key lug, the weakest part of the structure occurs at the point where the greatest strains occur, and this is most undesirable in devices of this nature.

It is among the special purposes of my present invention to provide a structure of back plate formed with an integral key lug, and wherein reinforcement is provided across the throat of the key lug, and in a most simple and efficient manner, thereby avoiding the objections noted and securing added strength at the point where the greatest strains occur.

In the drawings, I have shown an embodiment of my invention wherein 5 dcsignates the metal back plate, which, if desired, may be provided with the usual openings 6, therethrough to permit the metal of the cast shoe (not shown) to flush therethrough, in casting the shoe, to afford means for attaching the plate and shoe body together. Centrally of its length the plate is transversely folded or bent to form the integral key lug 7, the transverse walls 8, 9, of which having alined openings 10, formed through the metal thereof for the passage of the brake head locking key. In this arrangement of key slots or openings it will be seen that the entire bearing of the key is taken by the metal of the key lug itself, and this is a practical advantage as it secures strength, the strains being transmitted directly to the key through the key lug.

In one form of my invention, as shown in Figs. 1 and 2, the back plate 5 is pressed outwardly, at the lateral or side edges of the key lug, into transversely extending oif-sets or seats 11. Into these off-sets or seats are received 'the ends 14 of a reinforcing tie plate, which extends across the throat of the key lug and ties together the parts of the plate lying on opposite sides of the key lug. By pressing the ofl-se'ts or seats 11 in the plate on opposite sides of the key lug, and positioning the reinforcing tie plate therein, the inner surface of said tie plate is brought into flush relation with respect to the inner surface of the back plate. This reinforcing tie plate may have one or more openings 16 therethrough for the metal of the cast shoe body to flush through in casting the same to afford means for attaching the tie plate to the shoe body.

To reinforce the key lug, at the point of its lateral bend to form the walls thereof, the tie plate 14-, is centrally pressed outwardly and partially into the throat of the key lug 7. The top wall 15 of the tie plate is accordingly located well within the throat of the key lug.

In Fig. 3 I have shown my invention as applied to a back plate generally the same as hereinbefore described, but without the offsets or seats 11. It will be understood that the reinforcing tie plate may be secured to the back plate, if desired, and in any desired manner.

said plate having outwardly pressed portions adjacent the sides of said lug, to form Copies of this patent may be obtained for seats on its inner surface, and a tie plate received in said seats and spanning the throat of said lug, said tie plate having a portion thereof extending into the throat of the lug.

2. A back plate for brake shoes bent up transversely to form an integral key lug, said plate having, outwardly pressed portions adjacent the sides of said lug, to form seats on its inner surface, and a tie plate received in said seats and spanning the throat of said lug, said tie plate having a central extension pressed outwardly from the body thereof and extending into the throat of said lug.

3. A back plate for brake shoes bent up transversely to form an integral key lug, a reinforcing plate extending across the throat of said lug, said reinforcing plate having a central extension pressed outwardly from the body thereof and extending into the throat of said lug.

In testimony whereof I have hereunto set' my hand on this th day of September, A. D. 1916. l

WILLIAM H. MODONOUGH.

five cents eaioh, by addressing the Commissioner of Patents. Washington; D. G." 

